问如何使ConstraintLayout在安卓系统中可滚动？
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Stack Overflow用户

提问于 2017-09-10 17:52:21

回答 1查看 3.1K关注 0票数 0

我试图动态地向ConstraintLayout添加元素，使其可以滚动。我把ConstraintLayout包在ScrollView里。在插入元素之前，它看起来不错。但是，插入后，滚动视图不会展开，因此不会显示底部的某些元素。

https://i.imgur.com/PtND5uo.png按钮删除

<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:fillViewport="true"
    tools:context="com.example.abel.standingcalculator.MainActivity">
<android.support.constraint.ConstraintLayout
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    tools:layout_editor_absoluteX="0dp"
    tools:layout_editor_absoluteY="0dp">

    <Button
        android:id="@+id/calculate"
        android:layout_width="122dp"
        android:layout_height="48dp"
        android:layout_marginBottom="0dp"
        android:layout_weight="1"
        android:text="Calculate"
        app:layout_constraintBottom_toBottomOf="@+id/save"
        app:layout_constraintLeft_toRightOf="@+id/save"
        app:layout_constraintRight_toRightOf="parent" />

    <Button
        android:id="@+id/save"
        android:layout_width="125dp"
        android:layout_height="49dp"
        android:layout_marginBottom="0dp"
        android:layout_marginTop="40dp"
        android:layout_weight="1"
        android:text="Save"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toLeftOf="@+id/calculate"
        app:layout_constraintTop_toBottomOf="@+id/new_item"
        app:layout_constraintVertical_bias="0.325" />

    <EditText
        android:id="@+id/proportion1"
        android:layout_width="0dp"
        android:layout_height="36dp"
        android:layout_marginBottom="0dp"
        android:layout_marginEnd="8dp"
        android:layout_marginLeft="8dp"
        android:layout_marginRight="8dp"
        android:ems="10"
        android:inputType="numberDecimal"
        android:textSize="14sp"
        android:visibility="visible"
        app:layout_constraintBottom_toBottomOf="@+id/proportion_label1"
        app:layout_constraintHorizontal_bias="0.0"
        app:layout_constraintLeft_toLeftOf="@+id/item_name1"
        app:layout_constraintRight_toRightOf="parent" />

    <EditText
        android:id="@+id/sd1"
        android:layout_width="0dp"
        android:layout_height="36dp"
        android:ems="10"
        android:inputType="numberDecimal"
        android:textSize="14sp"
        android:visibility="visible"
        app:layout_constraintBottom_toBottomOf="@+id/sd_label1"
        app:layout_constraintHorizontal_bias="0.0"
        app:layout_constraintLeft_toLeftOf="@+id/proportion1"
        app:layout_constraintRight_toRightOf="parent" />

    <EditText
        android:id="@+id/mean1"
        android:layout_width="0dp"
        android:layout_height="36dp"
        android:ems="10"
        android:inputType="numberDecimal"
        android:textAlignment="center"
        android:textSize="14sp"
        app:layout_constraintBottom_toBottomOf="@+id/mean_label1"
        app:layout_constraintHorizontal_bias="0.0"
        app:layout_constraintLeft_toLeftOf="@+id/sd1"
        app:layout_constraintRight_toRightOf="parent" />

    <EditText
        android:id="@+id/total_grade1"
        android:layout_width="0dp"
        android:layout_height="36dp"
        android:layout_marginBottom="1dp"
        android:ems="10"
        android:inputType="numberDecimal"
        android:textAlignment="center"
        android:textAppearance="@style/TextAppearance.AppCompat.Medium"
        android:textColor="@android:color/black"
        android:textSize="14sp"
        app:layout_constraintBottom_toBottomOf="@+id/total_grade_label1"
        app:layout_constraintHorizontal_bias="0.0"
        app:layout_constraintLeft_toLeftOf="@+id/mean1"
        app:layout_constraintRight_toRightOf="parent" />

    <TextView
        android:id="@+id/item_name_label1"
        android:layout_width="41dp"
        android:layout_height="wrap_content"
        android:layout_marginLeft="20dp"
        android:layout_marginStart="16dp"
        android:layout_marginTop="30dp"
        android:text="Item Name"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <TextView
        android:id="@+id/proportion_label1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="16dp"
        android:layout_marginStart="16dp"
        android:layout_marginTop="20dp"
        android:text="Proportion"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/item_name_label1" />

    <TextView
        android:id="@+id/sd_label1"
        android:layout_width="60dp"
        android:layout_height="wrap_content"
        android:layout_marginLeft="16dp"
        android:layout_marginTop="20dp"
        android:text="Standard Deviation"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/proportion_label1" />

    <TextView
        android:id="@+id/mean_label1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="16dp"
        android:layout_marginStart="16dp"
        android:layout_marginTop="20dp"
        android:text="Mean"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/sd_label1" />

    <TextView
        android:id="@+id/total_grade_label1"
        android:layout_width="46dp"
        android:layout_height="wrap_content"
        android:layout_marginLeft="16dp"
        android:layout_marginTop="20dp"
        android:text="Total Grade"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/mean_label1" />

    <TextView
        android:id="@+id/your_grade_label1"
        android:layout_width="40dp"
        android:layout_height="wrap_content"
        android:layout_marginLeft="16dp"
        android:layout_marginStart="16dp"
        android:layout_marginTop="20dp"
        android:text="Your grade"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/total_grade_label1" />

    <EditText
        android:id="@+id/item_name1"
        android:layout_width="0dp"
        android:layout_height="36dp"
        android:layout_marginEnd="8dp"
        android:layout_marginLeft="32dp"
        android:layout_marginRight="8dp"
        android:layout_marginStart="32dp"
        android:ems="10"
        android:inputType="text"
        android:textAlignment="center"
        android:textSize="14sp"
        android:visibility="visible"
        app:layout_constraintBottom_toBottomOf="@+id/item_name_label1"
        app:layout_constraintHorizontal_bias="0.0"
        app:layout_constraintLeft_toRightOf="@+id/item_name_label1"
        app:layout_constraintRight_toRightOf="parent" />

    <Button
        android:id="@+id/new_item"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="8dp"
        android:layout_marginRight="8dp"
        android:layout_marginTop="38dp"
        android:text="Add New Item"
        app:layout_constraintHorizontal_bias="0.97"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/your_grade_label1" />

    <EditText
        android:id="@+id/your_grade1"
        android:layout_width="323dp"
        android:layout_height="36dp"
        android:ems="10"
        android:inputType="numberDecimal"
        android:textAlignment="center"
        android:textAppearance="@style/TextAppearance.AppCompat.Medium"
        android:textColor="@android:color/black"
        android:textSize="14sp"
        app:layout_constraintBottom_toBottomOf="@+id/your_grade_label1"
        app:layout_constraintHorizontal_bias="0.0"
        app:layout_constraintLeft_toLeftOf="@+id/total_grade1"
        app:layout_constraintRight_toRightOf="parent" />

    <android.support.constraint.Guideline
        android:id="@+id/guideline"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        app:layout_constraintGuide_begin="16dp"
        tools:layout_editor_absoluteX="16dp"
        tools:layout_editor_absoluteY="81dp" />
    <android.support.constraint.ConstraintLayout
        android:id="@+id/activity_main"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
    </android.support.constraint.ConstraintLayout>
</ScrollView>

编辑:这是动态添加的部分。

    mConstraintSet.clone(mConstraintLayout); // get constraints from ConstraintSet        }
    //item name label
    mConstraintSet.constrainHeight(item_name_label.getId(),
            ConstraintSet.WRAP_CONTENT);
    mConstraintSet.constrainWidth(item_name_label.getId(),
            toDp(41));
    int your_grade_id = (itemCount == 2) ? R.id.your_grade1 : ids.get("your_grade"+(itemCount-1));
    mConstraintSet.connect(item_name_label.getId(), ConstraintSet.TOP, your_grade_id,
            ConstraintSet.BOTTOM,toDp(40));
    mConstraintSet.connect(item_name_label.getId(), ConstraintSet.START, ConstraintSet.PARENT_ID,
            ConstraintSet.START,toDp(20));
    //for item name
    mConstraintSet.constrainHeight(item_name.getId(),
            toDp(36));
    mConstraintSet.constrainWidth(item_name.getId(),
            0);
    mConstraintSet.connect(item_name.getId(), ConstraintSet.BOTTOM, item_name_label.getId(),
            ConstraintSet.BOTTOM,0);
    mConstraintSet.connect(item_name.getId(), ConstraintSet.START, item_name_label.getId(),
            ConstraintSet.END, toDp(32));
    mConstraintSet.connect(item_name.getId(), ConstraintSet.END, ConstraintSet.PARENT_ID,
            ConstraintSet.END,0);
    //proportion
    mConstraintSet.constrainHeight(proportion_label.getId(),
            ConstraintSet.WRAP_CONTENT);
    mConstraintSet.constrainWidth(proportion_label.getId(),
            ConstraintSet.WRAP_CONTENT);
    mConstraintSet.connect(proportion_label.getId(), ConstraintSet.TOP, item_name_label.getId(),
            ConstraintSet.BOTTOM,toDp(20));
    mConstraintSet.connect(proportion_label.getId(), ConstraintSet.START, item_name_label.getId(),
            ConstraintSet.START,0);
    connect(mConstraintSet, proportion, item_name, proportion_label);
    //sd
    mConstraintSet.constrainHeight(sd_label.getId(),
            ConstraintSet.WRAP_CONTENT);
    mConstraintSet.constrainWidth(sd_label.getId(),
            toDp(60));
    mConstraintSet.connect(sd_label.getId(), ConstraintSet.TOP, proportion_label.getId(),
            ConstraintSet.BOTTOM,toDp(20));
    mConstraintSet.connect(sd_label.getId(), ConstraintSet.START, proportion_label.getId(),
            ConstraintSet.START,0);
    connect(mConstraintSet, sd, proportion, sd_label);
    //mean
    mConstraintSet.constrainHeight(mean_label.getId(),
            ConstraintSet.WRAP_CONTENT);
    mConstraintSet.constrainWidth(mean_label.getId(),
            ConstraintSet.WRAP_CONTENT);
    mConstraintSet.connect(mean_label.getId(), ConstraintSet.TOP, sd_label.getId(),
            ConstraintSet.BOTTOM,toDp(20));
    mConstraintSet.connect(mean_label.getId(), ConstraintSet.START, sd_label.getId(),
            ConstraintSet.START,0);
    connect(mConstraintSet, mean, sd, mean_label);
    //total grade
    mConstraintSet.constrainHeight(total_grade_label.getId(),
            ConstraintSet.WRAP_CONTENT);
    mConstraintSet.constrainWidth(total_grade_label.getId(),
            toDp(46));
    mConstraintSet.connect(total_grade_label.getId(), ConstraintSet.TOP, mean_label.getId(),
            ConstraintSet.BOTTOM,toDp(20));
    mConstraintSet.connect(total_grade_label.getId(), ConstraintSet.START, mean_label.getId(),
            ConstraintSet.START,0);
    connect(mConstraintSet, total_grade, mean, total_grade_label);
    //your grade
    mConstraintSet.constrainHeight(your_grade_label.getId(),
            ConstraintSet.WRAP_CONTENT);
    mConstraintSet.constrainWidth(your_grade_label.getId(),
            toDp(40));
    mConstraintSet.connect(your_grade_label.getId(), ConstraintSet.TOP, total_grade_label.getId(),
            ConstraintSet.BOTTOM,toDp(20));
    mConstraintSet.connect(your_grade_label.getId(), ConstraintSet.START, total_grade_label.getId(),
            ConstraintSet.START,0);
    connect(mConstraintSet, your_grade, total_grade, your_grade_label);
    //relocate buttons
    mConstraintSet.connect(R.id.new_item, ConstraintSet.TOP, your_grade_label.getId(),
            ConstraintSet.BOTTOM,toDp(40));
    mConstraintSet.connect(R.id.save, ConstraintSet.TOP, R.id.new_item,
            ConstraintSet.BOTTOM,toDp(40));
    mConstraintSet.connect(R.id.save, ConstraintSet.BOTTOM, ConstraintSet.PARENT_ID,
            ConstraintSet.BOTTOM,toDp(0));

    mConstraintSet.applyTo(mConstraintLayout);

希望这能提高代码的可读性。https://i.imgur.com/lYIXlVi.png

android

layout

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回答 1

Stack Overflow用户

发布于 2017-09-10 18:16:37

尝试像下面的代码一样设置height=0dp ..。

<android.support.constraint.ConstraintLayout 
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ScrollView
 android:layout_width="0dp"
 android:layout_height="0dp"
 app:layout_constraintLeft_toLeftOf="parent"
 app:layout_constraintRight_toRightOf="parent"
 app:layout_constraintTop_toTopOf="parent"
 android:layout_marginBottom="0dp"
 app:layout_constraintBottom_toTopOf="@+id/btnDone">

 <android.support.constraint.ConstraintLayout 
 xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">



    <TextView
        android:id="@+id/tvTest"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        tools:text="TESTTT" />
 </android.support.constraint.ConstraintLayout>
</ScrollView>
</android.support.constraint.ConstraintLayout>